This invention relates to flue baffles, and more particularly to flue baffles which may be removed from the small end of frusto-conical flues.
Water heating devices and the like often have a heat source, such as a gas burner, under a water storage tank. Exhaust gases and much of the heat created during combustion leave the heating device through a flue which extends through the center of the storage tank. Water in the storage tank is heated primarily in the bottom of the tank by the burner, and secondarily by the heat in the flue.
The efficiency of the heater may be improved by increasing heat transfer from the flue gas to the water. One way to increase efficiency is to use an upright frusto-conical flue having a large end near the burner and a small end near the top of the flue. Such a shape of the flue itself forces more of the flue gas heat against the walls of the flue as it rises. Efficiency may also be increased by adding a turbulator or a baffle to the inside of the flue. The turbulator or baffle may be any suitable form which directs heat towards the walls of the flue without excessively obstructing the flow of exhaust gases out of the heating device. Turbulating devices are described in U.S. Pat. Nos. 4,044,796 and 3,759,230.
Baffles may be used to direct heat toward the walls of the flue in heating devices which have straight or frusto-conical flues. Baffles for straight flues are described in U.S. Pat. Nos. 62,953, 257,139, 598,997, 753,900, 1,536,613, 1,677,630, 2,116,298 and 2,369,995. Baffles for other shapes of flues may be seen in U.S. Pat. Nos. 277,567, 1,101,872, and for a frusto-conical flue in U.S. Pat. No. 1,640,284.
If an upright frusto-conical flue is used in a heating device, and any of the baffle plates are larger than the small end of the flue, then the baffle must be installed in the flue from the large flue end, and it may not be removed without disassembling virtually the entire heating device. This will make the cleaning or repairing of the heating device much more difficult. Thus, there is a need for baffles which may be installed in and removed from frusto-conical flues through the small end of the flue.
Accordingly, an object of the present invention is to provide new and improved baffles for flues.
Another object is to provide new and improved baffles which may be installed in and removed from frusto-conical flues through the small end of the flue.